Surrounding schools are on lockdown as authorities investigate; police believe the gunman killed himself

In committing his unspeakable crime in Newtown, did Adam Lanza also reshape our approach to preventing — and responding to — active shooters in schools?

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CENTENNIAL, Colo. — The suspected gunman is dead after a shooting at Arapahoe High School, according to the Arapahoe County Sheriff Grayson Robinson.

Two students were shot. One is in serious condition, the other has minor injuries.

Robinson said he believes the suspect died from a self-inflicted gunshot wound.

Hundreds of students were evacuated safely. More are currently being evacuated.

The Sheriff's office tweeted that parents should go to Shepherd of the Hills Church at 7691 South University Blvd.

A witness told 7NEWS she saw police in riot gear at the scene.

Arapahoe High School is at 2201 East Dry Creek Road in Centennial.

Littleton Public Schools and Elizabeth schools have been placed on lockdown. Cherry Creek Schools are on secured perimeter, which means the outer doors are locked. Douglas County Schools is on lockout, which means there is increased alert, all doors locked, visitors need ID to get in and children will be dismissed at normal time with increased patrols. All public schools in Aurora have been placed on lockdown as a precaution, according to Aurora PD.